Stamp pad



Feb. 12, 1952 P. GORDON 2,585,647

STAMP PAD v Filed oct. 10. 1947 2 SHEETS-SHEET 1 Eg. Z

Zz-772277252" I Jym/Mm P. GORDON Feb. l2, 1952 STAMP PAD 2 Simms-SHEET 2 Filed OCC. l0, 1947 84M @moo/v Patented Feb. 12, 1952 UNITED S TAT/,ES PATENT OFFICE "2,585,64xz y l YSTAMP PAD VPaul Gordon, Chicagoflll. y Application-October 10, 1947, SerialrNo.l'779,f053

This invention Lrelates,..,to ra stamp .padeand more particularly to .the type of pad that is used assan ink pad for inking hand .stamps commonly referred to as rubber stamps.

the common .or conventionalform 4of stamp inking pad vin which the inkvor other fluidgis ,applied-to .the .top surface of the pad, thereis a tendency for that surface vto become -iobjectionably sticky, Vdue to' evaporationof .the inking-.fluid Thezusual type .of sponge rubber pad, moreover. isilikely to furnish theinking uid too :freely .when replenished, .or to :provide too .meagre asupply of ink before.beingreplenished.

L-In athe stamp .pad vconstruction of my present invention, -the base of the pad is provided with interconnecting reservoirs foncontainingtheinking'luid. The .pad itself is formedvof sponge rubberawithlay liquidimpervious skin-onitsxundervsurface. .The pad, however, is provided -withkselfsealing slits vthatwextend completely through the thickness of the pad and through the otherwise liquidmimpervious skin, with/,at least oneormore of ALsuchslits lyingi above eachfof the reservoirs or Wells in the base.

Consequently, when the rubbenstamp is'gpressed down against the upper-surface.of;theinkingpad, at'least lone' of the uself -sealing l sli-tsvfis openedup sufficiently to -feedinkfromthe adjacent reservoir up #into :the ybodyl of 'the -pad, -and thence by capillary-#action to the surface'lof the pad. J'By reason of this construction,V the main .supply-fof ink l`in thef-padispreventedfrom exposure to theair'an'd consequentl evaporation, except as fthe ink is brought to the surface -by use vofthe pad. --Replenishment nof :the rink supply -i-n lthe reservoirs in the base of Athe 'pad may ber-simply accomplishe'd--by inserting Aan eyedropper through the self-sealing slits and forcing the -ink-uid rfrom the'feyedropper into the Lreservoir therebelow. Since Lth'e yreservoirs 4are interconnecting, vthe ink uidwill flow ,into .albof the reservoirs, or, :las is more zlikely, the operator :will insert vkthe leyedrQppr throughaplurality of theslits to spread theinkiamongthe y various reservoirs or Wells.

tjis i herefore A`an important o -bject of, this in vention to provide ali-stamp in kng pad of `improved constructiontoobviate the diiculties and disadvantages of the stamping pads heretofore employed- It`is a ,'further importantobject of `this invention topro'vide a stamp inking `pad in which the the ,pad itself is A formed vof. sponge rubber` and is provided with selffsealing slits, and the base of the gp'ad is provided with interconnectingireserv'oirs. yor wells, from which the 'inking iluid #is .2 draw-n linto'fthe slits o f v the epad whenever -the pad is used. -Itis la further importantobjectof :this invention to,l provide -afstamping pad in v,which Vthe pad itself serves .to Eprevent vevaporation of the ink*fromythemainrsourceof supply of the ink in the base of the pad, the pad being provided with :a ,liquid impervious skin ron its under surface,;through which self-sealingslits extend :for permitting yink from :the reservoir to .be ldrawn into thepadgas'gthesamezis used.

It is afurther important object lof this -invention vsto:so:construct-.the:ink pad .that a relatively greatlsupply of. ink is incorporated lintheinlr pad assembly and :at the :same `time to protect such ink against evaporation While making the `ink available ffonuse asf-the pad itself is zused. Y

Other and further important objects of this invention willebe apparent from the disclosures in the specificationaand the accompanyingdrawings.

On l)the drawings:

Figure :1 is `aplan `view'l-.of -an ink ypad embodying ,the principles-"of my invention, with the cover removed.

Figurezissanendselevational view of thesame.

Figure .3 is a :plan Vview of the mounting .base of the ink ipad, rwiththelpad proper vLremoved.

.EigureA/isfa reduced sectional-view taken substantiallyalong the linelV--IVof Figure 1.

Figure 151i's4a fragmentary sectional view taken substantially along the line fV-V-of :Figure v3.

vFigure L6 .isa fragmentary -sectional view taken substantially along the zline VI--VI of Figure 1, with the section lines 4partially removed Vto -show the `construction #more clearly.

Figure 7 lis lanenlarged vfragmentary-plan view ofthespongeirubber pad illustratingvthe form-assumed v'by `the :self-sealing -slits :when the pad is stretched -under :tension vapplied transversely of the length of the slits FigureS isa sectional -view `taken substantially along vthe vline VIII-#VIII-IQof Figure 7.

Figure 9n is ian-enlarged -sectional view of the stamp pad illustrating-the action that takes place when the stamp, or inkreceiving-member is applied -to-thevsponge-rubber pad, as in the act-of inking the rubberfstamp.

`Figure A10 tis v4a fragmentary top plan view of the vstructure shown Figure 9,V Afurther illustrating the -action of vthe pad.

Figure 1,1 v'is fan -enlargedview of a portion of thepadillustrated'iniFigureS.

vThe reference numeral Ij5 jinjdicateS generally a stamp :pad 'embodying 'the `riririples Iof 'my plane vertical sidewalls I8 and with a plane bottom wall I9, 'which is provided with depressions,

or wells, 2B, connected by grooves 2|. As shown, the depressions or reservoirs 23 are segmental spherical in form and are separated'by the plane surface It, but are interconnected by the grooves 2i, which are of the same depth as the maximum depth of the wells 2G and that extend both longitudinally and transversely. Considered another way, the bottom wall of the base member has thereon upwardly facing spaced surface areas with intervening liquid reservoir spaces, and with the surface areas lying in substantially the same plane for supporting the skin 24 of the ink pad thereon.

The rectangular recess provided by the inner Walls I8 is adapted to receive a pad, which is indicated generally by the reference numeral 22. Said pad may be made from sponge rubber andis of such size as to lit the recess provided by the inner Walls I8 `and rest upon the surface I9, with its edges abutting the walls I8. The lateral edges of the pad are preferably sealed to the walls I8, fas indicated at 23 (Figs. 4 and 9). The sealing of the joint so formed between the pad proper andthe walls I8 prevents upward movement of the ink or other liquid at such joints.

The pad 22 is formed from commercially available sponge rubber that is furnished in relatively thick sheets that have on one surface a liquid impervious skin, indicated at 24 (Figs. 6, 8 and ll) In mounting the pad 22 in the base I6, the skin 24 is on the bottom and rests against the plane surfaces IQ; Thus, Vwhen the pad 22 is secured in position and the joint between the lateral edges of the pad and the inner Walls I8 sealed with a liquid-tight adhesive, or cement, as at 22, the reservoirs 2li and grooves 2| are in effect sealed against the entrance of air from outside, except as will now be explained.

The pad 22 is provided with a plurality of spaced slits 25, extending the long way of the pad, as

viewed, vand other slits 26, also spaced from each other and extending transversely of the slits 25 and spaced from said slits 25. The slits 25 and 26 extend completely through the pad and through the skin 24, being preferably arranged in symmetrical rows extending longitudinally and transversely of the pad. These slits are of such character that they are normally closed, except when a distorting force or pressure is applied to the pad. The arrangement of the slits 25 and 26 is such thatat least one of such slits, and usually several, is disposed over each reservoir 20. Y

Thus, when the pad 22 is compressed, or a portion thereof is depressed downwardly, as by the use of a stamp, S (Fig. 9) one or more of the slits 25 or 26 will open up at its lower edge, as at 26al (Fig. 11) thereby allowing ink to move in the opened slits and freely enter the spaces or voids of the sponge rubber. Once the slits 25 or 26 ref ceive the inking uid from the Wells or grooves 2l, the ilud is distributed by capillary action through the rubber pad to the upper surface thereof, which isv free from any skin Such as the skin 24. The slits 25 and 26 thus tend to produce uniform ink distribution throughout the area of the pad 22, and these slits also enable the ink supply in the reservoirs to be replenished when that becomes necessary. For that purpose, the ink can be introduced through one of the slits by means of an eyedropper.

Figures 9, l0 and ll illustrate the action that takes place when the stamp S is pressed down against the upper surface of the pad-22 and distortion of the pad takes place. As there shown, one of the slits 26 has opened up at the bottom, as at 26a, as a portion of the pad is depressed into one of the reservoirs 23. The ink uid within such reservoir 20 is thereupon caused to enter the opening 25a and be carried by capillarity up f through the porous body of the pad 22. Upon the release of the distorting force, the opening 26a closes again to entrap the amount of ink uid that has been picked up in the operation. In its normal position, the skin 2d is substantiallyim.- pervious to the flow of liquid therethrough, since all ofthe slits 25 and 26 are then closed. Thus, the ink within the reservoirs 2i! and the groove 2i is again sealed against the entrance of air beneath the pad 22 and will be retained in proper condition pending the need for replenishing the ink supply in the body of the pad 22.

The plane bottom surfaces I9 of the base I6 serve to support the pad in its normal position. This insures proper contact of the pad with the stamp S when the latter is applied to the ink pad in the normal or customary manner.

It will thus be apparent that the present invention provides an ink pad that is so constructed and arranged as to protect the main suppy of ink from evaporation or other changes due to exposure to the atmosphere, while at the same time making the supply of ink available in proper amounts as the pad is used in a normal or ordinary manner.

Instead of forming the pad 22 of sponge rubber, it may be formed of sponge-like regenerated cellulose or other cellular material of similar sponge-like properties.

I claim as my invention:

1. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall dening a recess having a generally at bottom surface, said bottom Wall having a plurality of spaced reservoirs formed therein as depressions opening through said flat bottom surface, said bottom Wall having channels formed therein connecting said reservoirs so as to permit ow of liquid between such connected reservoirs, a pad ymember formed from sponge rubber and having a liquid tight skin on one flat face thereof, said pad member:

being disposed in said recess with said liquid tight skin resting on said flat bottom surface vof said recess, adhesive means securing edge portions of said pad member to said Wallto form a liquidtight seal with said Wall about said edges, said pad member having a plurality of spaced self-closing slits extended therethrough and po#- sitioned so that at least one such slit is disposed over each of said reservoirs.

2. In a stamp pad, a base formed to afford an upstanding wall and a bottom wall defining a re` cess having a generally flat bottom surface, said bottom Wall having a plurality of spaced reservoirs formed therein as depressions opening through said fiat bottom surface, a pad member formed from sponge rubber and having a liquid' tight skin on one nat face thereof, said pad member being disposed in said recess with said liquid tight skir resting ,on said sflat bottom surface :of said recess, ladhesive means securing edgevporitonsof said .pad member to ksaid wall to A:form -a liquid-tightseal .with said Wall about said edges, said pad member having a plurality of spaced self-closing slits extended therethrough and positioned so that at least one such slit is disposed over each of said reservoirs.

3. In a stamp pad, a base formed to afford an upstanding wall and a bottom wall defining a recess having a generally fiat bottom surface, said bottom -Wall havingg-a-plurality of spaced reservoirs- .formed Y therein asxfdepressions ,open'ing through said dat,bottom..surface,:said bottomwall having channels formed therein connecting said reservoirs so as to permit flow of liquid between such connected reservoirs, a pad member formed from sponge rubber and having a liquid tight skin on one fiat face thereof, said pad member being disposed in said recess with said liquid tight skin resting on said fiat bottom surface of said recess, means forming a liquid tight seal between edge portions of said pad member and said recess, said pad member having a plurality of spaced self-closing slits extended therethrough and positioned so that at least one such slit is disposed over each of said reservoirs.

4. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall defining a recess having a generally fiat bottom surface, said bottom Wall having a plurality of spaced reservoirs formed therein as depressions opening through said hat bottom surface, a pad member formed from sponge rubber and having a liquid tight skin on one fiat face thereof, said pad member being disposed in said recess with said liquid tight skin resting on said fiat bottom surface of said recess, means forming a liquid tight seal between edge portions of said pad member and said recess, said pad member having a plurality of spaced self-closing slits extended therethrough and positioned so that at least one such slit is disposed over each of said reservoirs.

5. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall defining a recess having a generally fiat bottom surface, said bottom Wall having a plurality of spaced reservoirs formed therein as depressions opening through said fiat bottom surface, said bottom Wall having channels formed therein connecting said reservoirs so as to permit fiovvv of liquid between such connected reservoirs, a porous pad member disposed in said recess, a normally liquid tight resilient skin member disposed on said flat bottom surface so as to overlie said reservoirs and sealed to the surfaces of said recess about the edges of said skin member, said skin member having a plurality of self-closing slits formed therein so as to dispose at least one such slit over each of said reservoirs.

6. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall defining a recess having a generally fiat bottom surface, said bottom wall having a plurality of spaced reservoirs formed therein as depressions opening through said flat bottom surface, a pad member formed from sponge rubber and disposed in said recess so as to contact said Walls about the edges of the recess, a normally liquid tight resilient skin member disposed on said flat bottom surface so as to overlie said reservoirs and sealed to the surfaces of said recess about the edges of said skin member, said skin member having a vplurality of self-closing slits formed therein so as to dispose at least one such slit over each of said reservoirs.

'7. In a stamp pad, a base formed to afford an 6" upstan'dingfwall 'and Asa .bottom-wall defining arecess having a generally .at 'bottom surface, 1 said bottom Wall having a-plurality of spacedreservoirs formed therein .as depressions .opening througlrsaid fiat bottom surface, va'pad-member formed from spongerubber and *disposed in said recessso as tocontact said-Walls about vthe edges of fthe recess, a normally liquid tight resilient skin member :disposed onsaid flat bottom surface Vso as toi/overlie said reservoirs and sealed to :the surfaces of` said recess about the edges ,of said skin member, lsaid pad member and said skin member having a'plurality of aligned self-closing slits `formed ,therein so as to dispose at least one i, such slit over each of said reservoirs.

`8. In a stamp pad, a base formed to afford an upstanding Wall and a bottom wall defining a recess having a generally flat bottom Surface, said bottom Wall having :at least one depression r. formed therein and affording a reservoir opening through said at bottom surface, a pad member formed from sponge rubber and having a liquid tight skin on one fiat face thereof, said pad member being disposed in said recess with said liquid tight skin resting on said fiat bottom surface of said recess, adhesive means securing edge portions of said pad member to said wall to form a liquid tight seal with said wall about said edges, said pad member having at least one self-closing slit extended therethrough :and positioned so as to be disposed over said reservoir.

9. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall defining a recess having a generally flat bottom surface,

' said bottom Iwall having at least one depression formed therein and affording a reservoir opening through said flat bottom surface, a porous pad member disposed in said recess, a normally liquid tight resilient skin member disposed on said flat bottom surface so as to overlie said reservoir and sealed to the surfaces of said recess about the edges of said skin member, said skin member having at least one self-closing slit formed therein so as to be disposed over said reservoir.

10. In a stamp pad, a base formed to afford an upstanding wall and a bottom Wall defining a recess having a generally flat bottom surface, said bottom Wall having at least one reservoir formed therein as a depression opening through said fiat bottom surface, a pad member formed from sponge rubber and disposed in said recess so as to contact said Walls about the edges of the recess, a normally liquid tight resilient skin member disposed on said flat bottom surface so as to overlie said reservoir and sealed to the surfaces of said recess about the edges of said skin member, said pad member and said skin member having at least one pair of aligned self-closing slits formed therein so as to be disposed over said reservoir.

11. In a stamp pad, a base formed to afford an upstanding Wall and a bottom Wall defining a recess having a generally flat bottom surface, said bottom Wall having at least one reservoir formed therein as a depression opening through said flat bottom surface, a pad member formed from sponge rubber and disposed in said recess so as to contact said Wallsabout the edges of the recess, a normally liquid tight resilient skin member disposed on said flat bottom surface so as to overlie said reservoir and sealed to the surfaces of said recess about the edges of said skin member, said skin member having at least one self-closing slit formed therein so as to be disposed over said reservoir.

12; In'a stamp pad, a base having an upstanding lateral wall and a bottom wall dening therewith a pad-receiving recess, said bottom wall having thereon upwardly facing spaced surface areas `with intervening liquid reservoir spaces,

said surface areas lying in substantially the same plane, a pad member formed from sponge material and having a liquid tight skin on the under face thereof, said pad member being disposed in said recess with said liquid tight skin resting on i' said surface areas and being secured at its lateral edges to said upstanding lateral wall to form aliquid-tight seal with said Wall about said edges, and said pad member having a plurality of spaced REFERENCES CITED The following references are of record in the Y le of this patent:

K UNITED STATES PATENTS Number Name Date 1,702,003 Harris Feb. 12, 1929 1,815,371 Edgarton July 21, 1931 2.374.198

Harris Apr. 24, 1945 

